1. Field of the Invention
The present invention relates to an improved process for the preparation of organosilanes and organopolysilanes from organodisilanes.
2. Description of the Prior Art
Various processes for the preparation of organosilanes and/or optionally hydroorganosilanes from organohalodisilanes are already known to this art.
In particular, various methods of processing residues from the direct synthesis of methylchlorosilanes (reaction of methyl chloride with silicon in the presence of copper, described in U.S. Pat. Nos. 2,380,995 and 2,488,487) which consist of mixtures of compounds including, among others, disilanes, are described, for example in French Pat. Nos. 1,093,399, 2,163,579 and 2,163,579.
Thus, according to French Pat. No. 1,093,399, disilanes are cleaved by heating at a temperature of from 200.degree. to 300.degree. C. in the presence of hydrochloric acid.
According to French Pat. No. 2,163,579, a disilane is reacted with a halide in the presence of platinum or palladium, or a phosphine complex of platinum, palladium and nickel.
And according to French Pat. No. 2,342,981, disilanes are reacted with hydrogen gas under pressure in the presence of an aprotic base such as hexamethylphosphoric triamide.
While the known processes indeed enable the preparation of the organosilanes/organopolysilanes, they nevertheless display at least one of the following disadvantages:
(i) the process requires conditions of temperature or pressure which render industrial application difficult and costly;
(ii) the catalysts and/or the reactants employed are toxic, costly and/or unstable in air; and
(iii) the reaction time is too long and/or the yields are but mediocre.